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f30c2269 | 1 | /* linux/drivers/i2c/busses/scx200_i2c.c |
1da177e4 LT |
2 | |
3 | Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> | |
4 | ||
5 | National Semiconductor SCx200 I2C bus on GPIO pins | |
6 | ||
7 | Based on i2c-velleman.c Copyright (C) 1995-96, 2000 Simon G. Vogl | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 2 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
14 | This program is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with this program; if not, write to the Free Software | |
21 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
22 | */ | |
23 | ||
401e72b5 JC |
24 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
25 | ||
1da177e4 LT |
26 | #include <linux/module.h> |
27 | #include <linux/errno.h> | |
28 | #include <linux/kernel.h> | |
1da177e4 LT |
29 | #include <linux/i2c.h> |
30 | #include <linux/i2c-algo-bit.h> | |
21782180 | 31 | #include <linux/io.h> |
1da177e4 LT |
32 | |
33 | #include <linux/scx200_gpio.h> | |
34 | ||
1da177e4 LT |
35 | MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>"); |
36 | MODULE_DESCRIPTION("NatSemi SCx200 I2C Driver"); | |
37 | MODULE_LICENSE("GPL"); | |
38 | ||
39 | static int scl = CONFIG_SCx200_I2C_SCL; | |
40 | static int sda = CONFIG_SCx200_I2C_SDA; | |
41 | ||
42 | module_param(scl, int, 0); | |
43 | MODULE_PARM_DESC(scl, "GPIO line for SCL"); | |
44 | module_param(sda, int, 0); | |
45 | MODULE_PARM_DESC(sda, "GPIO line for SDA"); | |
46 | ||
47 | static void scx200_i2c_setscl(void *data, int state) | |
48 | { | |
49 | scx200_gpio_set(scl, state); | |
50 | } | |
51 | ||
52 | static void scx200_i2c_setsda(void *data, int state) | |
53 | { | |
54 | scx200_gpio_set(sda, state); | |
55 | } | |
56 | ||
57 | static int scx200_i2c_getscl(void *data) | |
58 | { | |
59 | return scx200_gpio_get(scl); | |
60 | } | |
61 | ||
62 | static int scx200_i2c_getsda(void *data) | |
63 | { | |
64 | return scx200_gpio_get(sda); | |
65 | } | |
66 | ||
67 | /* ------------------------------------------------------------------------ | |
68 | * Encapsulate the above functions in the correct operations structure. | |
69 | * This is only done when more than one hardware adapter is supported. | |
70 | */ | |
71 | ||
72 | static struct i2c_algo_bit_data scx200_i2c_data = { | |
a0d9c63d JD |
73 | .setsda = scx200_i2c_setsda, |
74 | .setscl = scx200_i2c_setscl, | |
75 | .getsda = scx200_i2c_getsda, | |
76 | .getscl = scx200_i2c_getscl, | |
77 | .udelay = 10, | |
082a4cf8 | 78 | .timeout = HZ, |
1da177e4 LT |
79 | }; |
80 | ||
81 | static struct i2c_adapter scx200_i2c_ops = { | |
82 | .owner = THIS_MODULE, | |
4a029abe | 83 | .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, |
1da177e4 LT |
84 | .algo_data = &scx200_i2c_data, |
85 | .name = "NatSemi SCx200 I2C", | |
86 | }; | |
87 | ||
88 | static int scx200_i2c_init(void) | |
89 | { | |
401e72b5 | 90 | pr_debug("NatSemi SCx200 I2C Driver\n"); |
1da177e4 LT |
91 | |
92 | if (!scx200_gpio_present()) { | |
401e72b5 | 93 | pr_err("no SCx200 gpio pins available\n"); |
1da177e4 LT |
94 | return -ENODEV; |
95 | } | |
96 | ||
401e72b5 | 97 | pr_debug("SCL=GPIO%02u, SDA=GPIO%02u\n", scl, sda); |
1da177e4 LT |
98 | |
99 | if (scl == -1 || sda == -1 || scl == sda) { | |
401e72b5 | 100 | pr_err("scl and sda must be specified\n"); |
1da177e4 LT |
101 | return -EINVAL; |
102 | } | |
103 | ||
104 | /* Configure GPIOs as open collector outputs */ | |
105 | scx200_gpio_configure(scl, ~2, 5); | |
106 | scx200_gpio_configure(sda, ~2, 5); | |
107 | ||
108 | if (i2c_bit_add_bus(&scx200_i2c_ops) < 0) { | |
401e72b5 | 109 | pr_err("adapter %s registration failed\n", scx200_i2c_ops.name); |
1da177e4 LT |
110 | return -ENODEV; |
111 | } | |
112 | ||
113 | return 0; | |
114 | } | |
115 | ||
116 | static void scx200_i2c_cleanup(void) | |
117 | { | |
3269711b | 118 | i2c_del_adapter(&scx200_i2c_ops); |
1da177e4 LT |
119 | } |
120 | ||
121 | module_init(scx200_i2c_init); | |
122 | module_exit(scx200_i2c_cleanup); | |
123 | ||
124 | /* | |
125 | Local variables: | |
126 | compile-command: "make -k -C ../.. SUBDIRS=drivers/i2c modules" | |
127 | c-basic-offset: 8 | |
128 | End: | |
129 | */ |